HOUSTON — Celebrity chefs Emeril Lagasse and Rachael Ray reign over vast empires that include popular television shows and cookbooks, but their reach now extends beyond kitchens on Earth — to outer space.

The chefs were tapped by U.S. space agency NASA to create recipes for two recent space shuttle missions as part of a bid to boost morale among the astronauts and to raise public awareness of the program, said the manager of NASA’s food laboratory at Johnson Space Center.

While everyone back on Earth might not aspire to understand the scientific complexities of the latest shuttle mission, most identify with what astronauts eat, said Michele Perchonok, who oversees the effort to develop food for astronauts in Houston.

“Everybody eats. It’s a great common denominator,” Perchonok said of the agency’s use of celebrity chefs to raise public awareness among groups who might not normally track the space shuttle’s progress.

Ray’s Swedish meatballs, spicy Thai chicken and vegetable curry were eaten by the crew of the space shuttle Discovery in December.

Lagasse’s jambalaya, mashed potatoes with bacon, green beans, rice pudding and fruit were eaten by astronauts on the International Space Station in August.

The recipes are tested and processed for space at NASA, where they were dehydrated and packaged for reformulation.

NASA scientists tasked with taking the chefs’ recipes and turning them into space food encountered only a few snags. For example, Ray’s meatballs had to made smaller so the astronauts would have an easier time eating them in space, Perchonok said.

Slideshow: Planetary pleasures
Jeff Williams, an Expedition 13 flight engineer who was on the space station when Lagasse’s food was served, remembers the day as a good one with the astronauts talking to the chef via satellite for a taping of his show on the Food Network.

“It obviously wasn’t a primary work event, but it was a great thing to do to boost the morale of the crew,” he said.

Williams’ wife and son participated in the broadcast, which helped them reconnect after months apart, the astronaut said. Space station astronauts are typically away for six months.

Karen Katz, the executive producer of “Emeril Live,” said NASA first called Lagasse to ask for tips on spicing up space food because palates in space change but he and others on the show thought it would be a thrill to create recipes for them.

As for working with NASA again Katz said there are no firm deals, but “the door is certainly open.”